Recent evidence has shown that astrocytes, a subset of glia, are capable of introducing and propagating calcium waves in vitro. Astrocyte processes are in close contact with synapses and can alter synaptic activity through regulation of glutamate in the perisynaptic space. The ability of astrocytes to propagate waves and alter synaptic activity suggest that these cells play active roles in brain signaling. Currently, astrocyte characterization has been based on morphological studies, whereas expression profiling of neurons has resulted in distinct classifications of cells based on the genes they express, which is often related to localization and function within the brain. Astrocyte subtypes may also exist in coordination with their neuronal partners. Therefore, we hypothesize that distinct astrocyte expression subtypes exist in the brain that are important for proper brain signaling and function. Using single-cell RNA amplifcation and DNA-array methods, we intend to develop an expression profile for primary astrocytes from different locations of the brain. Our laboratory has been successful in detecting both active translation and transcript specificity in dendrites. Likewise, we intend to identify the presence of active translation in astrocyte processes and identify what subset of mRNA transcripts are localized to the astrocyte processes. Expression profiling of astrocyte and astrocyte processes will provide a benchmark for future studies in characterizing these cells and may provide insight on pathological conditions thought to involve astrocyte dysfunction, such as multiple sclerosis, Parkinson's disease, and glioma.